Lesinurad (CAS: 878672-00-5, RDEA594), as a urate-lowering agent, was firstly reported by Ardea Biosciences Inc. in patent application (WO2009070740), the synthetic route thereof was shown as below.
Synthetic Route 1:

In the subsequent several patent applications (WO2011085009, WO2011126852, WO201159732, WO2012050589, WO2012092395, WO2014008295), the manufacture of Lesinurad and the corresponding salt form, as well as the combo-therapy of Lesinurad with cocichicines, febuxostat and allopurinol and the like were all reported in details by Ardea Biosciences Inc.
Another preparation method for Lesinurad and the intermediate(s) was also reported in patent application CN103524440A, as shown below.
Synthetic Route 2:

In these published patent applications, no clear description about Lesinurad as a mixture of axially chiral atropisomers was available, neither details of separation technology, asymmetric synthesis technology and specific characterization data of these two atropisomers were reported ever.